Design and Evolution of Metal-Based Functions in Supramolecular Protein Scaffolds

金属蛋白执行许多对生物学和人类健康至关重要的细胞功能。虽然我们的 由于技术的进步，金属蛋白如何发挥作用的知识已经大大增加，我们仍然 对蛋白质结构/动力学和金属之间的相互作用只有肤浅的理解 配位/反应性。因此，还不可能a）预测 B）模仿或改进金属蛋白的结构和功能 金属蛋白的从头设计，和c）了解复杂的生物无机功能可能具有 在自然进化过程中出现在简单的肽/蛋白质支架上。拟议的《行动纲领》的总体目标 研究计划是通过设计和构建蛋白质支架来解决这三个挑战， 越来越复杂的金属基功能灵感来自于一个假设的自然路径 为了研究金属蛋白的进化，我们最近开发了金属蛋白设计的新方法， 单体蛋白质被金属离子模板化以形成新的超分子组装体。的接口 这些在进化上幼稚的复合物经过改造和进化， 具有复杂金属基功能的体系结构。在拟议的研究中，我们将进一步发展这些 利用我们实验室开发的两种新蛋白质支架， （DiCyt和TriCyt），其提供了容易获得不同的金属配位几何结构、次级球 环境和全局属性（可调结构，低聚状态，柔性/刚性），难以 其他蛋白质设计策略。我们将使用DiCyt和TriCyt支架构建金属蛋白 用于稳定和选择性配位第一行过渡金属离子的组装件（具体目标1），用于挑战 酯、酰胺和磷酸酯键水解反应（具体目标2），以及氧化还原催化反应 涉及分子氧结合和活化（具体目标3）。这些努力不仅将揭示基本的 结构-功能关系，支配不同的金属蛋白活性，但也导致更好地了解 生物无机复杂性如何出现在简单的蛋白质支架中。

Metalloproteins carry out many cellular functions that are central to biology and human health. While our knowledge of how metalloproteins function has grown immensely thanks to technological advances, we still possess only a superficial understanding of the interplay between protein structure/dynamics and metal coordination/reactivity. As a result, it has not yet been possible a) to predict the functional mechanism of metalloproteins simply by looking at their structures, b) to emulate or improve upon the structures and functions of metalloproteins by de novo design, and c) to understand how complex bioinorganic functions may have emerged on simple peptide/protein scaffolds during natural evolution. The overarching goal of the proposed research program is to address these three challenges by designing and constructing protein scaffolds with increasingly more complex metal-based functions from scratch. Inspired by a hypothetical pathway for the natural evolution of metalloproteins, we have recently developed new approaches to metalloprotein design in which monomeric proteins are templated by metal ions to form novel supramolecular assemblies. The interfaces of these evolutionarily naïve complexes are then engineered and evolved to create self-standing protein architectures with complex metal-based functions. In the proposed research, we will further develop these “metal-templated protein design” strategies by capitalizing on two new protein scaffolds developed in our lab (DiCyt and TriCyt), which provide easy access to diverse metal coordination geometries, secondary-sphere environments and global properties (tunable structures, oligomeric states, flexibility/rigidity) that are difficult to attain with other protein design strategies. We will use DiCyt and TriCyt scaffolds to build metalloprotein assemblies for stable and selective coordination of first-row transition metal ions (Specific Aim 1), for challenging ester, amide and phospho-ester bond hydrolysis reactions (Specific Aim 2), and for redox catalytic reactions involving dioxygen binding and activation (Specific Aim 3). These efforts will not only uncover fundamental structure-function relationships that govern diverse metalloprotein activities, but also lead to better understanding of how bioinorganic complexity emerges in simple protein scaffolds.